1,916 research outputs found
Transfinite tree quivers and their representations
The idea of "vertex at the infinity" naturally appears when studying
indecomposable injective representations of tree quivers. In this paper we
formalize this behavior and find the structure of all the indecomposable
injective representations of a tree quiver of size an arbitrary cardinal
. As a consequence the structure of injective representations of
noetherian -trees is completely determined. In the second part we will
consider the problem whether arbitrary trees are source injective
representation quivers or not.Comment: to appear in Mathematica Scandinavic
Estimation of Purcell factor from mode-splitting spectra in an optical microcavity
We investigate scattering process in an ultra-high-Q optical microcavity
coupled to subwavelength scatterers by introducing "splitting quality" Qsp, a
dimensionless parameter defined as the ratio of the scatterer-induced mode
splitting to the total loss of the coupled system. A simple relation is
introduced to directly estimate the Purcell factor from single-shot measurement
of transmission spectrum of scatterer-coupled cavity. Experiments with
polystyrene (PS) and gold (Au) nanoparticles, Erbium ions and Influenza A
virions show that Purcell-factor-enhanced preferential funneling of scattering
into the cavity mode takes place regardless of the scatterer type.
Experimentally determined highest Qsp for single PS and Au nanoparticles are
9.4 and 16.19 corresponding to Purcell factors with lower bounds of 353 and
1049, respectively. The highest observed Qsp was 31.2 for an ensemble of Au
particles. These values are the highest Qsp and Purcell factors reported up to
date.Comment: 5 Pages, 4 Figures, 12 Reference
Photonic multipartite entanglement conversion using nonlocal operations
We propose a simple setup for the conversion of multipartite entangled states
in a quantum network with restricted access. The scheme uses nonlocal
operations to enable the preparation of states that are inequivalent under
local operations and classical communication, but most importantly does not
require full access to the states. It is based on a flexible linear optical
conversion gate that uses photons, which are ideally suited for distributed
quantum computation and quantum communication in extended networks. In order to
show the basic working principles of the gate, we focus on converting a
four-qubit entangled cluster state to other locally inequivalent four-qubit
states, such as the GHZ and symmetric Dicke state. We also show how the gate
can be incorporated into extended graph state networks, and can be used to
generate variable entanglement and quantum correlations without entanglement
but nonvanishing quantum discord.Comment: 10 pages, 6 figures, correction of reference list, add Journal ref.
and DO
Observation of quantum interference in the plasmonic Hong-Ou-Mandel effect
We report direct evidence of the bosonic nature of surface plasmon polaritons
(SPPs) in a scattering-based beamsplitter. A parametric down-conversion source
is used to produce two indistinguishable photons, each of which is converted
into a SPP on a metal-stripe waveguide and then made to interact through a
semi-transparent Bragg mirror. In this plasmonic analog of the Hong-Ou-Mandel
experiment, we measure a coincidence dip with a visibility of 72%, a key
signature that SPPs are bosons and that quantum interference is clearly
involved.Comment: 5 pages, 3 figure
Pathological yawning in patients with acute middle cerebral artery infarction: Prognostic significance and association with the infarct location
Background: Pathological yawning is a compulsive, frequent, repetitive yawning triggered by a specific reason besides fatigue or boredom. It may be related to iatrogenic, neurologic, psychiatric, gastrointestinal, or metabolic disorders. Moreover, it could also be seen in the course of an ischemic stroke. Aims: To determine whether pathological yawning is a prognostic marker of middle cerebral artery stroke and evaluate its relationship with the infarct location. Study Design: Cross-sectional study. Methods: We examined 161 patients with acute middle cerebral artery stroke, consecutively admitted to emergency department. Demographic information, stroke risk factors, stroke type according to Trial of Org 10172 in Acute Stroke Treatment classification, blood oxygen saturation, body temperature, blood pressure, heart rate, glucose levels, daytime of stroke onset, National Institutes of Health Stroke Scale score (National Institutes of Health Stroke Scale score, at admission and 24 h), modified Rankin scale (at 3 months), and infarct locations were documented. Pathological yawning was defined as ?3 yawns/15 min. All patients were observed for 6 hours to detect pathological yawning. National Institutes of Health Stroke Scale score >10 was determined as severe stroke. The correlation between the presence of pathological yawning and stroke severity, infarct location, and the short-and long-term outcomes of the patients were evaluated. Results: Sixty-nine (42.9%) patients had pathological yawning and 112 (69.6%) had cortical infarcts. Insular and opercular infarcts were detected in 65 (40.4%) and 54 (33.5%) patients, respectively. Pathological yawning was more frequently observed in patients with cortical, insular, and opercular infarcts (p<0.05). Pathological yawning was related to higher National Institutes of Health Stroke Scale scores. Patients with severe stroke (National Institutes of Health Stroke Scale score ?10) presented with more pathological yawning than those with mild to moderate strokes (p<0.05). The clinical outcomes and mortality rates showed no significant relationship with the occurrence of pathological yawning. Conclusion: Pathological yawning in middle cerebral artery stroke was associated with stroke severity, presence of cortical involvement, and insular and opercular infarcts. However, no association was found with long-term outcome and mortality. ©Copyright 2020 by Trakya University Faculty of Medicine / The Balkan Medical Journal published by Galenos Publishing House
Quantum random number generation using an on-chip nanowire plasmonic waveguide
Quantum random number generators employ the inherent randomness of quantum
mechanics to generate truly unpredictable random numbers, which are essential
in cryptographic applications. While a great variety of quantum random number
generators have been realised using photonics, few exploit the high-field
confinement offered by plasmonics, which enables device footprints an order of
magnitude smaller in size. Here we integrate an on-chip nanowire plasmonic
waveguide into an optical time-of-arrival based quantum random number
generation setup. Despite loss, we achieve a random number generation rate of
14.4 Mbits/s using low light intensity, with the generated bits passing
industry standard tests without post-processing. By increasing the light
intensity, we were then able to increase the generation rate to 41.4 Mbits/s,
with the resulting bits only requiring a shuffle to pass all tests. This is an
order of magnitude increase in the generation rate and decrease in the device
size compared to previous work. Our experiment demonstrates the successful
integration of an on-chip nanoscale plasmonic component into a quantum random
number generation setup. This may lead to new opportunities in compact and
scalable quantum random number generation.Comment: 10 pages, 3 figures, appendi
The effect of CoQ10 and vitamin E on serum total sialic acid, lipid-bound sialic acid, some trace elements and minerals in rats induced with doxorubicin
This study was designed to evaluate the effect of CoQ10 and vitamin E on serum total sialic acid (TSA), lipid bound sialic acid (LSA) and some elements in rat administered doxorubicin (DXR). Cu levels were increased in the group treated with DXR + vitamin E in comparison with DXR (p<0.05) and CoQ10 groups (p = 0.001). Furthermore, copper levels were increased in the group treated with DXR + CoQ10 in comparison with CoQ10 group (p < 0.05). Zn levels were decreased in the group treated with DXR + vitamin E in comparison with CoQ10 group (p < 0.05). Mg levels were decreased in subjects treated with DXR + vitamin E in comparison with the control group values (p < 0.05). Particularly, the observed increase in Cu levels in rats from DXR + vitamin E group might be due to the decrease of vitamin E. However, the oxidative damage could be as a result of DXR occurence and may be helpful to clinicians in chemotherapy using anthracycline.Key words: Doxorubicin, total sialic acid (TSA), lipid bound sialic acid (LSA), trace elements, minerals
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